The invention relates to a conveyor comprising an axle extending along a longitudinal axis, a drum body mounted rotatably about the longitudinal axis on the axle, a drive unit comprising an electrical drive motor which is disposed inside the drum body and which includes a rotor and a stator, wherein either one of the rotor or the stator is coupled torque-resistantly with a drive output shaft which is mounted rotatably about a drive axle and the other one of said rotor and stator is a torque support and is coupled torque-resistantly with the axle, and a connector member which is disposed inside the drum body and torque-resistantly coupled with the drum body and the drive output shaft of the drive motor.
Conveyors of this kind are used for different purposes and in different designs. A conveyor according to the invention may be a drum motor, for example, or a roller drive. Drum motors are deployed, for example, in such a way that they are mounted in a frame by means of the axle, which is then attached stationarily in relation to the frame and torque-resistantly to the frame. The drum body rotatably mounted on the axle is driven by means of the drive unit inside the drum body and made to rotate. The drive unit is supported by the axle and is connected with the drum body on the driven side. The drum motor can be used to drive other devices by means of a belt drive or the like, for example a conveyor line consisting of a plurality of conveyor rollers. The drum motor can also be used directly as a conveyor element in a conveyor line and can carry the conveyed item and convey it by rotation of the drum body. Another use is to dispose the drum motor as a drive element at the end of a conveyor belt system and to guide a conveyor belt which is partly wrapped around the drum body and to make it move by rotation of the drum body.
Drum motors with different driving power are known from the prior art. The driving power ranges from about 10 W to 6 KW and can transmit a torque of up to 1000 Nm via the drum body. Due to their particular construction, drum motors are characterized by the specific problem of heat being difficult to dissipate from the drive means, which is disposed inside the drum body for compact construction. For some drum motors with high power ratings, filling the drum body with oil is therefore an established technique in the prior art for ensuring that the drum motor remains thermally stable even under heavy loads. As a basic principle, however, it is possible to dispense with filling the drum body with oil even when such components are used, due to higher levels of efficiency.
In contrast to drum motors, roller drives are generally equipped with a drum body of smaller diameter, referred to as a roller body or pipe, and typically have a power rating of less than 100 W, typically in the range between 10 and 40 W. Such roller drives are used to carry and convey items in roller conveyor lines. Roller conveyors can be combined with a plurality of idle rollers arranged in parallel, which are driven by the motor-driven or similarly driven conveyor roller via a belt drive or chain drive, as the case may be. In curved roller conveyors, the rollers are arranged with their axes at an angle to each other.
Drum motor and roller conveyor drives are frequently used in environments in which they are used for conveying articles in production facilities, in a logistics distribution center, or in a warehouse. In such environments, it is generally desirable that as little noise is produced by the conveyor systems installed and operated there, so as not to disturb people who work in the area near such production or logistics facilities.
To that end, it is known from the prior art to equip drum motors and motor-driven conveyor rollers with a drive unit that partly makes use of plastic elements for force transmission, in particular in the drive section of the drive output shaft and in any gear mechanism that may be disposed there. For example, it is known from the prior art that the noise produced by gear transmissions can be reduced by using plastic gear wheels on one or both sides for the various gear ratios. The disadvantage of such a construction, however, is that the transmittable power is reduced because of the lower durability of the plastic gear wheels in the drive train, and that the service life is shorter.
Mounting drum motors and motor-driven conveyor rollers in encapsulated sections in order to reduce noise emissions from conveyor lines containing such drum motors or motor-driven conveyor rollers is also known from the prior art. Such an encapsulated conveyor line is practicable for a number of applications, but when the conveyed items must be accessible to people, such an encapsulated conveyor line can only be achieved in a very impracticable manner such that access to the items is possible. Conveyor lines with an encapsulated design are also a constructionally complex and cost-intensive solution.